Clustering 115 Hop Varieties: Part 2

Recipe Building

TL;DR: I designed the recipes for each of the 4 hop varieties I chose in the previous installment, Pacifica, Helga, Challenger, and HBC 682.

Introduction:

So, here are my goals and recipes for this experiment, resulting from calculating a distance metric and k-means clustering 115 hop varieties. Hops were selected based on the distances calculated from information collected from YCH Hops. The most distanced (i.e. “different”) hops (Pacifica & HBC 682), closest “sibling” to one of those hops (Helga, from Pacifica), and the “most average” hop of all (Challenger) were selected. Note: I will adjust the recipes when the hops come in after ordering as the alpha acid percentage varies by specific lot. Yet here lies my rationale behind the recipes:

Goals & Considerations:

Normalize the bitterness contribution so that all recipes have the same IBU contribution based on the alpha acid percentage and isomerization time. When I run the tasting/evaluation event, I don’t want the level of bitterness to influence the perceived character of the bitterness.

Pellet hops from the same supplier and harvest year will be used. Considering the southern hemisphere has a different harvest season than the northern, this is a possible issue based on AA% loss over time, and it would be interesting to cluster hops from a single region and harvest season. That will have to be done at a different time.

I want a well rounded expression of the hop; so I will have a 60 minute, 10 minute, whirlpool, and dry hop addition. IBU contributions at the whirlpool stage will happen during wort chilling at 170 degrees F (77C). Dry hopping will be done the primary fermentation vessel after a full 2 weeks of fermentation after it clears a bit. Since there are so many compounds present in hops that can contribute to aroma in a beer, the best I can do to normalize dry hop aroma contributions is to calculate based on the average total oil for each hop.

For example, Pacifica has an average of 1.0 mL of total oil for 100g of hops, so if I plan to use 2.0 oz (57 g) of hops, I am targeting 0.57 mL of total oil for dry hopping. HBC 682 has an average of 1.5 mL/100g, which is higher than Pacifica, so I will use less hops. This calculates to dry hopping with 1.38 oz (38 g) of HBC 682.

An IPA would probably be the most obvious choice of style, so I’m targeting an OG of 1.060, IBU of 50 (Tinseth), and as much as I’d like to add a pinch of light munich and vienna malt, I’m going to stick to a SMaSH beer.

I want as neutral as possible backdrop for the hops, so I will use a hop-forward water profile from Brewer’s Friend (below), Briess pale brewers malt (2-row), and California Ale Yeast (WLP001). Calculated actual water profile, which will be closer to the actual ion content is posted below this list. I am too cheap to buy RO water or make a RO filter to get the ions closer to the target.

Beer is overflowing from my keezer and my beer shelf, so I’m only making 3 gallon batches which will be bottled. This will provide 25-30 bottles per hop type. Bottling is better for this exercise as it will be easier to do a tasting in a consistent manner for all tasters involved. Most likely all the beer will be used for tastings, hopefully 2 people per set of 4 bottles, I just need to find 40 people or so, which might not be too difficult in my brew club.

Reduce the amount of variability. Unfortunately, each beer will be done in succession, one batch a day over 4 days. I’m interested in seeing how the 4 brew days compare, especially if there are any incidents or discrepancies along the way. Fermenting will be done in my basement, which hovers around 68 degrees F (20 C). Bottled beer will be stored in my basement to carb for 2 weeks. Not sure when tasting will happen, so any variability as a result of those 4 days will even out as time goes on.